In digital circuits, synchronizers that prevent metastability and synchronize data across different unrelated clock domains may suffer from unpredictable data transfer delays across the domains. In designs that use such signals as relative time stamps or, alternatively, where such signals have to be applied or released within a deterministic time, significant phase and latency error margins have to be taken care of.
For example, a basic synchronizer that may include series-coupled flip-flops (FFs) may be used to prevent metastability and to minimize mean time between failures (MTBF). This arrangement may result in unpredictable phase offsets and may suffer from minimum pulse width constraints.